Apparatus and method for the manufacture of twisted and plied yarn

ABSTRACT

In a spinning operation in which two strands are fed from separate nip positions and are twisted together into a single ply at a convergence point, twist is incorporated into the single strands by intermittently blocking the twist at a position between the convergence point of the strands and the point of application of the twist. The operation can be performed by a standard spinning frame modified to incorporate a convergence guide and a twist blocking device.

United States Patent [19] Plate et al.

[ 1 Oct. 29, 1974 1 1 APPARATUS AND METHOD FOR THE MANUFACTURE OFTWISTED AND PLlED YARN [75] lnventors: Dieter Erich Alexander Plate,

Torquay, Victoria; John Desmond Feehan, Newton, Victoria, both ofAustralia [73] Assignee: Commonwealth Scientific and Industrial ResearchOrganization, Campbell, Australia [22] Filed: Apr. 6, 1973 [21] Appl.No; 348,818

[30] Foreign Application Priority Data Apr. 12, 1972 Australia 8583/72[52] US. Cl. 57/34 AT, 57/38.3, 57/39, 57/75, 57/114, 57/160 [51] Int.Cl. D01h 13/08, D02g 3/26, DOZg 3/28 [58] Field of Search 57/6, 13, 14,34 R, 34 AT, 57/36, 38.3, 34, 75, 90, 91, 114, 156, 160

[56] References Cited UNITED STATES PATENTS 386,623 7/1888 Boyd 57/912,948,931 8/1960 Smith 57/91 UX 3,144,747 8/1964 Palm et al 57/91 X3,176,351 4/1965 Keen 57/91 X 3,394,538 7/1968 Neff 57/38.3 3,415,04812/1968 Welbers 57/34 AT 3,695,019 10/1972 Lappage S7/38.3

Primary Examiner-Donald E. Watkins Attorney, Agent, or Firm-Sughrue,Rothwell, Mion, Zinn and Macpeak [5 7] ABSTRACT In a spinning operationin which two strands are fed from separate nip positions and are twistedtogether into a single ply at a convergence point, twist is incorporatedinto the single strands by intermittently blocking the twist at aposition between the convergence point of the strands and the point ofapplication of the twist. The operation can be performed by a standardspinning frame modified to incorporate a convergence guide and a twistblocking device.

15 Claims, 3 Drawing Figures APPARATUS AND METHOD FOR THE MANUFACTURE OFTWISTED AND PLIED YARN BACKGROUND OF THE INVENTION This inventionrelates to the production of textile yarns and in particular to yarns ofa multi-ply structure in which at least two individual strands of fibresare combined in such a way that the compound structure contains twist inthe individual strands as well as plying twist. The objectives in usingmulti-ply yarns and twofold yarns in particular, rather than singlesyarns is to improve the performance of the yarns in subsequent processessuch as weaving and to enhance the properties of the resulting fabrics.This invention aims to produce such a yarn in a single spinningoperation.

In the ensuing discussion, reference will be made to the twist in thestrands and in the plied two-fold yarns. It will be realised that theexistence and direction of twist is relative to the viewing position ofthe observer; throughout this specification, the twist will be describedwith reference to the axis of the plied yarn or the individual strand asthe case may be, as seen by a stationary observer from a positiondisplaced laterally from the yarn.

Yarns of the type disclosed herein, in which at least two strands aretwisted together while incorporating singles twist into each of thestrands, are usually intended for weaving into normal fabrics and arepreferably uniform in the sense that at any position along the length ofthe yarn the single strands are wound substantially equally about oneanother with neither predominating.

PRIOR ART U.S. Pat. No. 3,695,019 discloses a process for forming a yarncomprising at least two strands plied together, wherein there is twistin each of the individual strands. In the process described therein,single strands emerging from separate feeding points of a draftingmechanism are twisted together at a convergence point which is moved soas to cyclically vary the distance between the convergence point and thefeeding points while at the same time the rates of feeding each strandto the convergence point are maintained substantially equal. Thisprocess produces a yarn structure in which the plying twist between thestrand is maintained in a given direction, but varies cyclically inintensity along the length of the structure and in which each of thestrands is itself twisted with twist of cyclically varying direction andintensity.

SUMMARY OF THE INVENTION It is an object of this invention to provide asimple process and apparatus for producing, in a single twistingoperation, a yarn comprising at least two strands plied together,wherein there is twist in each of the individual strands.

A particular object of the invention is to provide a simpler and morecompact apparatus than that described in U.S. Pat. No. 3,695,019 for theproduction of yarn of the type disclosed therein.

In accordance with the invention there is provided a process forproducing a yarn, comprising at least two strands plied together, andwherein there is twist in each of the individual strands. The processcomprises the steps of separately feeding each strand from a feedingpoint and converging them at a convergence point, twisting the strandstogether, and intermittently blocking the twist at a position betweenthe convergence point of the strands and the point of application of thetwist.

The strands are preferably both fed from a single conventional draftingunit, the feeding points being preferably arranged so that they aresymmetrical about a plane passing through the convergence point.

The invention also provides apparatus for producing a yarn comprising atleast two strands plied together, and wherein there is twist in eachindividual strand, which apparatus comprises means for separatelyfeeding each strand from a feeding point, convergence means forconverging the separate strands, twisting means for applying twist tothe converged strands to twist them together, and intermittentlyoperable twist blocking means for effecting intermittent blocking of thetwist at a position between the convergence means and the point ofapplication of the twist.

One apparatus suitable for application of the invention comprisesessentially a standard spinning frame having drafting mechanisms eacharranged to deliver a strand through a conventional thread guide, suchas a simple pot-eye, to the traveller of a conventional ring spindle.

In this application, each drafting unit is modified to supply twoseparate strands to a convergence guide where they are plied togetherand spun on to the spindle as a two-fold yarn. Without furthermodification, a yarn of the double-rove type, with only very littlerandomly occurring strand twist would then be produced. Modification ofsuch an apparatus for operation according to this invention may becarried out as shown in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic frontelevational view of part of a spinning frame modified according to thisinvention;

FIG. 2 is a cross-sectional view of such an apparatus taken on a linesimilar to line 2-2 in FIG. 1', and

FIG. 3 is a somewhat exaggerated diagrammatic view of a yarn accordingto this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT The spinning frame includes anyconventional drafting secion, such as the double apron systems shown inFIG. 1, including front drafting rollers 2, which draft a pair ofstrands 3,3 and feeds them through pot-eye 4 to a cap or ring spinningspindle 6. To this extent the apparatus is a conventional apparatus.

In accordance with the invention, the apparatus is modified by providinga convergence guide 12 at the point Y and, at a point between thepot-eye 4 and the convergence guide 12, a pair of rollers 7, 8 arrangedto be rotated at a peripheral speed substantially equal to the deliveryspeed of the yarn and to provide an intermittent nip between them.

One of the rollers 7 is a plain roller whilst the other roller 8 has asection 11 cut out from one side over part of its length and positionedsuch that the yarn will pass through it. The convergence guide 12 islocated at approximately the position which would be occupied by thenatural convergence of the strands if the rollers 7,8 were not operativeand may typically be of the order of 3 cm. from the points at which thestrands are nipped by the front drafting rollers.

In operation, the strands 3,3 are drafted by the front drafting rollers2 of the drafting mechanism, and fed to the convergence guide 12, theroller pair 7,8 the poteye" 4, on to the spindle 6. The spinningparameters are chosen such that with the rollers 7,8 inoperative and theyarn passing through the relieved section 11 on the roller 8, thenatural convergence point of the yarns would be at or about theconvergence guide 12. With the rollers 7 and 8 rotating, the nippingtogether of the two rollers over the unrelieved section of the roller 8causes a twist block to be inserted between the spindle and theconvergence guide 12. This periodically blocks the application of twistalong the converged strands to the point Y. Thus, the application oftwist to the individual strands at the point Y is periodically varied,and we have discovered that this periodic variation of the applicationof twist to the strands at the convergence point causes cyclicallyvarying twist to be inserted into the single strands passing through thepoint Y and causes the resultant ply to have cyclically varyingunidirectional twist. The resultant yarn is illustrated in FIG. 3. Itwill be seen that there are cyclically recurring regions A, B in theplied structure in which the twist in the ply is respectively high andlow. It will be observed also that in the regions A, of high twist, thetwist in the individual strands is opposite to that in the ply and inthe regions B, of low twist, the strand twist is of the same directionas that of the ply.

There is thus produced by the method and apparatus of this invention, ayarn comprising two plied components and in which there is twist in thecomponents themselves. This can be achieved according to this inventionby a very simple modification of a conventional spinning frame.

EXAMPLE 1 Two 390 tex Rovings of 22 micron wool with a mean fibre lengthof 65 mm. were drafted on one double apron drafting unit to produce twostrands of 18/5 tex each. The separation of the strands was 18 mm. andthey were combined at a convergence guide 12 situated 28 mm. below thenip of the front drafting rollers 2. From the convergence guide thecombined strands passed through the intermittent twist-blocking rollers7 and 8, then via a pot-eye 4 to a conventional ringspindle with a ringdiameter of 55 mm. The nip line of the twist blocking rollers was 80 mm.from the front roller nip and the diameter of the relieved roller was 32mm. with one-half of the circumference of the roller relieved. A twistof 650 tpm was inserted at a spindle speed of 9,000 R.P.M. and 2.5spinning breaks were recorded per 100 spindle hours.

The yarns were then steamed and cleared and without further treatmentwarped and woven on a Saurer Loom. The weave was 2 X 2 hopsack and 2/2twill stripe with 29.1 ends per cm. and 27.2 picks per cm. 0.22 weavingbreaks per 1,000 ends per 10,000 picks were recorded.

The yarns contained an average strand twist of 4.5 turns per /&-cyclelength being cm. The coefficient of variation of eveness of the yarn was16.1 percent and the tenacity was 6.98 gf/tex.

EXAMPLE 2 Two 390 tex rovings of 22 micron wool with a mean fibre lengthof mm. were drafted on one double apron drafting unit to produce twostrands of 29 tex each. The separation of the strands was 18 mm. andthey were combined at a convergence guide 12 situated 30 mm. below thenip of the front drafting rollers. From the convergence guide thecombined strands passed through the intermittent twist blocking rollers7 and 8 then via a pot-eye to a conventional ring spindle with a ringdiameter of 55 mm. The nip line of the twist blocking rollers was mm.from the front roller nip and the diameter of the relieved roller was 32mm. with one-half of the circumference of the roller relieved. A twistof 510 tpm was inserted at a spindle speed of 9,000 R.P.M. and 1.6spinning breaks per spindle hours were recorded.

The yarns were then steamed and cleared and without further treatmentused for the warp in the porduction of a Barathea fabric. Weavingperformance and fabric properties were comparable to those obtained withconventional two fold yarns.

The yarns contained an average twist of three turns per one-half cycle,the cycle length being 10 cm. The coefficient of variation of eveness ofthe yarns was 13.9 percent and the tenacity was 7.56 gf/tex.

We claim;

1. A process for producing a yarn, comprising at least two strands pliedtogether, and wherein there is twist in each individual strand, whichprocess comprises the steps of separately feeding each strand from afeeding point, converging the strands at a convergence point, twistingthe strands together, and intermittently blocking the twist at aposition between the convergence point of the strands and the point ofapplication of the twist.

2. A process according to claim 1, wherein the twist is blocked bynipping the converged strands between two co-operating nipping members.

3. A process according to claim 1, wherein the feeding points are bothdisposed on a single conventional drafting unit.

4. A process according to claim 1, wherein the rates of feeding of thestrands from their respective feeding points are substantially equal.

5. A process according to claim 1, wherein the feeding points arearranged so that the strands are disposed symmetrically about a planepassing through the convergence point.

6. A process for producing a yam, comprising at least two strands pliedtogether, and wherein there is twist in each individual strand, whichprocess comprises the steps of separately feeding each strand from afeeding point, twisting the strands together, and, at a position betweenthe convergence point of the strands and the point of application of thetwist, intermittently nipping the converged strands between twoco-operating nipping members said feeding points being arranged so thatthe strands are disposed symmetrically about a plane passing through theconvergence point.

7. Apparatus for producing a yarn comprising at least two strands pliedtogether and wherein there is twist in each individual strand, whichapparatus comprises means for separately feeding each strand from afeeding point, convergence means for converging the separate strands,twisting means for applying twist to the converged strands to twist themtogether, and intermittently operable twist blocking means for effectingintermittent blocking of the twist at a position between the convergencemeans and the point of application of the twist.

8. Apparatus according to claim 7, wherein the twist blocking meanscomprises a pair of co-operating nipping members arranged tointermittently nip the converged strands therebetween.

9. Apparatus according to claim 8, wherein the nipping members comprisea pair of rollers arranged to form a nip between them, at least one ofsaid rollers having a relieved portion on its circumference such that onrotation of the rollers the nipping of twisted strands is renderedintermittent by said relieved portron.

10. Apparatus according to claim 7 wherein the feeding points are bothdisposed on a single conventional drafting unit.

11. Apparatus according to claim 7 wherein the rates of feeding of thestrands from their respective feeding points are substantially equal.

12. Apparatus according to claim 7, wherein the means for feeding eachstrand are so arranged that the strands are disposed symmetrically abouta plane passing through the convergence point.

13. Apparatus for producing a yarn comprising at least two strands pliedtogether and wherein there is twist in each individual strand, whichapparatus comprises means for separately feeding each strand from afeeding point, convergence means for converging the separate strands,twisting means for applying twist to the converged strands to twist themtogether, and, at a position between the convergence means and the pointof application of the twist, a pair of co-operating nipping membersarranged to intermittently nip the converged strands therebetween, themeans for feeding each strand being so arranged that the strands aredisposed symmetrically about a plane passing through the convergencepoint.

14. Apparatus according to claim 13, wherein the nipping memberscomprise a pair of rollers arranged to form a nip between them, at leastone of said rollers having a relieved portion on its circumference suchthat on rotation of the rollers the nipping of twisted strands isrendered intermittent by said relieved portron.

15. Apparatus according to claim 13, wherein the the feeding points areboth disposed on a single conventional drafting unit.

1. A process for producing a yarn, comprising at least two strands pliedtogether, and wherein there is twist in each individual strand, whichprocess comprises the steps of separately feeding each strand from afeeding point, converging the strands at a convergence point, twistingthe strands together, and intermittently blocking the twist at aposition between the convergence point of the strands and the point ofapplication of the twist.
 2. A process according to claim 1, wherein thetwist is blocked by nipping the converged strands between twoco-operating nipping members.
 3. A process according to claim 1, whereinthe feeding points are both disposed on a single conventional draftingunit.
 4. A process according to claim 1, wherein the rates of feeding ofthe strands from their respective feeding points are substantiallyequal.
 5. A process according to claim 1, wherein the feeding points arearranged so that the strands are disposed symmetrically about a planepassing through the convergence point.
 6. A process for producing ayarn, comprising at least two strands plied together, and wherein thereis twist in each individual strand, which process comprises the steps ofseparately feeding each strand from a feeding point, twisting thestrands together, and, at a position between the convergence point ofthe strands and the point of application of the twist, intermittentlynipping the converged strands between two co-operating nipping memberssaid feeding points being arranged so that the strands are disposedsymmetrically about a plane passing through the convergence point. 7.Apparatus for producing a yarn comprising at least two strands pliedtogether and wherein there is twist in each individual strand, whichapparatus comprises means for separately feeding each strand from afeeding point, convergence means for converging the separate strands,twisting means for applying twist to the converged strands to twist themtogether, and intermittently operable twist blocking means for effectingintermittent blocking of the twist at a position between the convergencemeans and the point of application of the twist.
 8. Apparatus accordingto claim 7, wherein the twist blocking means comprises a pair ofco-operating nipping members arranged to intermittently nip theconverged strands therebetween.
 9. Apparatus according to claim 8,wherein the nipping members comprise a pair of rollers arranged to forma nip between them, at least one of said rollers having a relievedportion on its circumference such that on rotation of the rollers thenipping of twisted strands is rendered intermittent by said relievedportion.
 10. Apparatus according to claim 7 wherein the feeding pointsare both disposed on a single conventional drafting unit.
 11. Apparatusaccording to claim 7 wherein the rates of feeding of the strands fromtheir respective feeding points are substantially equal.
 12. Apparatusaccording to claim 7, wherein the means for feeding each strand are soarranged that the strands are disposed symmetrically about a planepassing through the convergence point.
 13. Apparatus for producing ayarn comprising at least two strands plied together and wherein there istwist in each individual strand, which apparatus comprises means forseparately feeding each strand from a feeding point, convergence meansfor converging the separate strands, twisting means for applying twistto the converged strands to twist them together, and, at a positionbetween the convergence means and the point of application of the twist,a pair of co-operating nipping members arranged to intermittently nipthe converged strands therebetween, the means for feeding each strandbeing so arranged that the strands are disposed symmetrically about aplane passing through the convergence point.
 14. Apparatus according toclaim 13, wherein the nipping members comprise a pair of rollersarranged to form a nip between them, at least one of said rollers havinga relieved portion on its circumference such that on rotation of therollers the nipping of twisted strands is rendered intermittent by saidrelieved portion.
 15. Apparatus according to claim 13, wherein the thefeeding points are both disposed on a single conventional drafting unit.